I would like to offer you some advice if that's helpful… all the work you poured on the creature gets stolen by the picture you used for the background. It's a very poor quality photo! specially contrasts with the amount of sharp details on your subject.

I suggest you, if you want to keep using photos, to look for them at high res. You can apply them some blur for the far distances, but the detailing on the first layer (the closest to the creature) must remain consistent with the creature. The grass you added helps the subject to blend into the image: if you put a mask on the bases of the grass, you can blend them more softly to the photo with a gradient

I think you are quite right about the quality of the pic! It is a crop of a photo which I found on the net, re-sized it to a large one,then altered it as much as it was possible! The foreground and the grasses are added separately.Unfortunately I don't have access to high resolution pics,so I have to make with what i can afford.But I'm thinking of creating my in backgrounds in Vue xstream if I can.

About the mask on the grass bases,may I ask what kind of mask would suit it better?on how could I use gradient on them?I appreciate any help on this.

Oh, and it's not necessary to buy photos, there are many high res (or at least, with nice resolutions) images out there! it's a matter of looking. It also helps to start with the picture and then drawing the character and not the other way round (because many elements clash! like light, pose… etcetera)